Confused about Android API's and compatability

I have purchased an HTC Incredible and have dived into the world of android! Only to find myself totally confused about the API levels and backward compatibility.

My device runs the 2.1 OS, but I know that most of the devices out there run 1.5 or 1.6; and soon the 2.2 OS will be running on new devices. The SDK has gone through such enormous changes, that even constants have been renamed (from VIEW_ACTION to ACTION_VIEW for example). Methods have been added and removed (onPause replacing the earli开发者_StackOverflower call, etc al).

So, If I want to write an application that will work from 1.6+, does that mean I have to install and write my code using the 1.6 API; then test on later versions? Or can I write using the 2.1 SDK and just set the minSDK level and not use "new" features?

I have never worked with an SDK that changes SO drastically from release to release! So I am not sure what to do....

I read through an article on the Android Development site(and this posting on stack overflow that references it: Should a legacy Android application be rebuilt using SDK 2.1?), but it was still not very clear to me. Any help would be appreciated

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The SDK has gone through such enormous changes, that even constants have been renamed (from VIEW_ACTION to ACTION_VIEW for example). Methods have been added and removed (onPause replacing the earlier call, etc al).

Those were two years ago, on a beta version of the platform, before there were any shipping devices. Since Android 1.0, there has been very little that breaks forward compatibility, mostly in the area of settings that were moved into a secure API so SDK applications cannot mess with them.

So, If I want to write an application that will work from 1.6+, does that mean I have to install and write my code using the 1.6 API; then test on later versions? Or can I write using the 2.1 SDK and just set the minSDK level and not use "new" features?

You make it seem like those are mutually exclusive. In fact, they are largely identical.

• Keep your toolset on the latest version of the Android development tools
• Put the minSdkVersion in your manifest to state what is the lowest API level you want to support
• Put the targetSdkVersion in your manifest to state what your "target" API level is, so Android can apply some compatibility helpers if your app runs on a newer version of Android (typically, you "target" the then-current API level)
• Write your code mostly to the API level you specified in minSdkVersion, optionally using reflection or conditional class loading to access newer APIs on devices that support them
• Test on everything you can get your hands on, at least emulators for the different API levels

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You can use the current SDK and set minSDK level to whatever level you want. If you do this then you cannot use any functionality that is not in the minSDK. It is also a good idea though to test it on all versions of the SDK with the emulator.

<uses-sdk minSDK="4" targetSDK="8"/>

That lets it know that you are targeting 2.2 but the minimum SDK level you want your app to run on is 1.6. By doing that you can use some of the new xml stuff in the newer versions like supports-screen and different drawables for different screens, etc.